Field
This disclosure is generally related to the aggregation of data from a plurality of devices. More specifically, this disclosure is related to the aggregation of encrypted data in a star network.
Related Art
The proliferation of the Internet and e-commerce continues to create a vast amount of digital content from a large number of devices. Individual contributors can send their local data to an aggregation entity, which can aggregate such data for measurement. For example, power consumption data can be aggregated by a utility company from a large number of smart meters. Similarly, health monitoring entities can compute statistical measures on fitness-related data provided by wearables (e.g., smartwatches) and smartphones, and online entities can obtain statistics on browser activity from Internet users.
Although users may consent to the aggregation of individual data in return for value-added services, the users may be reluctant to share personal information about their individual behavior. In the above examples, power usage data reveal information about the homeowner's daily patterns, fitness data may reveal sensitive medical information, and browser activity can reveal intimate details of an individual's life. The main privacy constraint in this interaction between untrusted entities is that the data held by any individual user should not be revealed to any other participant or the aggregator.
To facilitate secure aggregation, each user should obfuscate its input so that all the obfuscated inputs can later be combined by the aggregator to compute the aggregated value. However, in a star connected topology, users don't communicate with each other. As a result, a user can only encrypt its local data using its own unique key, which is unknown to any other entity.